Interpretive Summary: The application of poultry litter to agricultural soils may exacerbate losses of trace elements in runoff water, an emerging concern to water quality. We evaluated trace elements (arsenic, cadmium, copper, lead, manganese, mercury, selenium and zinc) in surface runoff and leachate during two rainfall simulations from an agricultural soil with three litter aplication methods (broadcast application, subsurface placement, and broadcast application followed by disking) and compared them to a no-litter control. Notably, incorporating litter, either by disking after broadcasting or by subsurface placement, lowered As and Zn in runoff to near background levels by the second rainfall event. While Hg and Se were detected in runoff, they likely derived from edaphic sources as they were not detected in the litter nor did they differ significantly between treatments. Results point to poultry litter as a temporary source of some trace elements to runoff that is readily controlled by adjusting application method.

Technical Abstract:
The application of poultry (Gallus gallus domesticus) litter to agricultural soils may exacerbate losses of trace elements in runoff water, an emerging concern to water quality. We evaluated trace elements (arsenic, cadmium, copper, lead, manganese, mercury, selenium and zinc) in surface runoff and leachate from an agricultural soil with and without poultry litter application. Litter from a commercial operation was applied by three methods ¬– broadcast application, subsurface placement, and broadcast application followed by disking – to no-till soils with a history of receiving litter. Soil monolith lysimeters (61 x 61 x 61cm) were extracted from each of the treatments and subjected to rainfall simulation (1 hr, 61 mm h-1) 15 and 42 days after litter application. Cadmium, Cu, Mn, and Pb were not detected in runoff water, presumably due to their low concentration in the applied litter. Broadcasting poultry litter significantly increased concentrations (mg L-1) and loads (g ha-1) of As and Zn in runoff during the first event relative to other application methods. Notably, incorporating litter, either by disking after broadcasting or by subsurface placement, lowered As and Zn in runoff to near background levels by the second event, and there were no significant differences in As and Zn between any of the treatments. While Hg and Se were detected in runoff, they likely derived from edaphic sources as they were not detected in the litter nor did they differ significantly between treatments. Results point to poultry litter as a temporary source of some trace elements to runoff that is readily controlled by adjusting application method.